Touch-sensing, I2C and 10-bit ADC in an 8-pin 8-bit MCU

March 25, 2013 // By Paul Buckley
Microchip Technology Inc., has added to the company’s PIC12/16F15XX 8-bit microcontroller (MCU) family with the low-cost, low pin count PIC12LF1552 is Microchip’s smallest (2x3 mm UDFN package) and lowest-cost PIC MCU with hardware I2C support.

The device includes a four channel 10-bit Analog-to-Digital Converter with hardware Capacitive Voltage Divider support for capacitive touch sensing.  

Additionally, the new MCU features 3.5 KB Flash program memory, 256 Bytes RAM, a 32 MHz internal oscillator, low-voltage operation from 1.8 V to 3.6 V, and low power consumption for active and sleep currents of 50 µA/MHz and 20 nA, respectively.

The hardware CVD enables a more efficient implementation of capacitive sensing for touch applications.  The ‘Core-Independent Peripheral’ includes additional control logic that enables automated sampling, which reduces software size and minimizes CPU usage.  The device also provides automatic control of guard-ring drive and a programmable sample-and-hold capacitance, to better match larger touch or proximity sensors.  The capabilities, combined with the low cost and small footprint of the PIC12LF1552, make it well suited for applications such as temperature-monitoring devices, small remote controls (e.g., garage doors and window blinds), smartphone buttons (e.g., input interfaces for Android and Windows 8 phones utilizing hardware CVD), room light control (e.g., switching and dimming, both taking advantage of hardware CVD), and coffeemakers (e.g., input interfaces and water-level monitoring, which both could utilize the hardware CVD and the integrated communication capabilities), among others.

Availability and Pricing

The PIC12LF1552 MCU is offered in 8-pin PDIP, SOIC, MSOP and 2x3x0.5 mm UDFN packages.  It is available today for sampling and volume production.

Microchip’s full suite of development tools support the PIC12LF MCUs, including the MPLAB X Integrated Development Environment (IDE), and PICkit 3 (part # PG164130, $44.95), MPLAB REAL ICE In-Circuit Emulator (part # DV244005, $499.98), and MPLAB ICD 3 (part # DV164035, $189.99) programmers.  Additionally, the MPLAB XC8 Compiler for 8-bit PIC MCUs now supports this device.

More information about Microchip 8-bit MCUs at